10,783 research outputs found
S-4B orbital workshop attitude control system study
Saturn S-4B orbital workshop attitude control system analysi
Study of radiation hazards to man on extended near earth missions
Radiation hazards to man on extended near earth mission
Problem areas in the use of the firefly luciferase assay for bacterial detection
By purifying the firefly luciferase extract and adding all necessary chemicals but ATP in excess, an assay for ATP was performed by measuring the amount of light produced when a sample containing soluble ATP is added to the luciferase reaction mixture. Instrumentation, applications, and basic characteristics of the luciferase assay are presented. Effect of the growth medium and length of time grown in this medium on ATP per viable E. coli values is shown in graphic form, along with an ATP concentration curve showing relative light units versus ATP injected. Reagent functions and concentration methods are explored. Efforts to develop a fast automatable system to detect the presence of bacteria in biological fluids, especially urine, resulted in the optimization of procedures for use with different types of samples
CFT fusion rules, DHR gauge groups, and CAR algebras
It is demonstrated that several series of conformal field theories, while
satisfying braid group statistics, can still be described in the conventional
setting of the DHR theory, i.e. their superselection structure can be
understood in terms of a compact DHR gauge group. Besides theories with only
simple sectors, these include (the untwisted part of) c=1 orbifold theories and
level two so(N) WZW theories. We also analyze the relation between these models
and theories of complex free fermions.Comment: 22 pages, LaTeX2
Evanescent Black Holes
A renormalizable theory of quantum gravity coupled to a dilaton and conformal
matter in two space-time dimensions is analyzed. The theory is shown to be
exactly solvable classically. Included among the exact classical solutions are
configurations describing the formation of a black hole by collapsing matter.
The problem of Hawking radiation and backreaction of the metric is analyzed to
leading order in a expansion, where is the number of matter fields.
The results suggest that the collapsing matter radiates away all of its energy
before an event horizon has a chance to form, and black holes thereby disappear
from the quantum mechanical spectrum. It is argued that the matter
asymptotically approaches a zero-energy ``bound state'' which can carry global
quantum numbers and that a unitary -matrix including such states should
exist.Comment: 14 page
Critical Statistical Charge for Anyonic Superconductivity
We examine a criterion for the anyonic superconductivity at zero temperature
in Abelian matter-coupled Chern-Simons gauge field theories in three
dimensions. By solving the Dyson-Schwinger equations, we obtain a critical
value of the statistical charge for the superconducting phase in a massless
fermion-Chern-Simons model.Comment: 11 pages; to appear in Phys Rev
Breeding Ecology and Behavior of the Hawaiian Hawk
We studied the ecology of the endangered Hawaiian Hawk (Buteo solitarius) on the island of Hawaii for three breeding seasons. Their breeding strategy is a prime example of a K-selected species characteristic of many birds in tropical environments: clutch size was one and brood-rearing was among the longest reported for any diurnal raptor. Twenty-eight nests were found in a variety of native and exotic habitats. Incubation lasted 38 days, nestlings fledged after 59-63 days, and parents cared for fledglings for an average of 30.2 weeks, which was 2.5 to 10 times longer than similar-size temperate zone raptors. Males assisted females with incubation, but only females brooded young. Radio-tagged juveniles remained within 0.63 km of their nests for the first two months after fledging, after which dispersal distances expanded gradually. Avian (45%) and mammalian (54%) prey dominated the diet of nestlings. There was no evidence that avian malaria, introduced predators, or environmental contaminants were affecting their population. Based upon estimates of population size, the availability of suitable nesting habitat, and reproductive success, we suggest the species be considered for downlisting from endangered to threatened status
Online tools for assessing the climatology and predictability of rainfall and temperature in the Indo-Gangetic plains based on observed datasets and seasonal forecast models
Rainfall in the Northern India-Nepal-Bangladesh region is crucial for farmers, water managers and others in the region. Most precipitation falls predominantly during the south Asian summer monsoon season. The phase of El Niño-Southern Oscillation (ENSO) affects the monsoon as well as winter rainfall in some of the region, but the spring predictability barrier and weakness of ENSO-monsoon relationships lead to relatively low-to-moderate seasonal forecast skill in the region during summer. This report documents a set of tools developed to facilitate the analysis of the mean climate and the predictability of seasonal climate in the region and presents preliminary results for the summer monsoon season. These tools advance the tailoring of historical and forecast climate information for agriculture and increase the accessibility of the information via online map rooms to benefit stakeholders throughout the region
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